Added marker positioning and rendering. Not tested yet.

src/ve/ucv/ciens/ccg/nxtar/NxtARCore.java

@@ -15,9 +15,9 @@
  */
 package ve.ucv.ciens.ccg.nxtar;
 
-import ve.ucv.ciens.ccg.nxtar.interfaces.CVProcessor;
+import ve.ucv.ciens.ccg.nxtar.interfaces.ImageProcessor;
 import ve.ucv.ciens.ccg.nxtar.interfaces.ApplicationEventsListener;
-import ve.ucv.ciens.ccg.nxtar.interfaces.OSFunctionalityProvider;
+import ve.ucv.ciens.ccg.nxtar.interfaces.AndroidFunctionalityWrapper;
 import ve.ucv.ciens.ccg.nxtar.network.RobotControlThread;
 import ve.ucv.ciens.ccg.nxtar.network.SensorReportThread;
 import ve.ucv.ciens.ccg.nxtar.network.ServiceDiscoveryThread;
@@ -116,12 +116,12 @@ public class NxtARCore extends Game implements ApplicationEventsListener{
 	/**
 	 * <p>The OpenCV wrapper.</p>
 	 */
-	public CVProcessor cvProc;
+	public ImageProcessor cvProc;
 
 	/**
 	 * <p>Wrapper around the Operating System methods.</p>
 	 */
-	private OSFunctionalityProvider osFunction;
+	private AndroidFunctionalityWrapper osFunction;
 
 	// Networking related fields.
 	/**
@@ -206,14 +206,14 @@ public class NxtARCore extends Game implements ApplicationEventsListener{
 
 		// Check if the concrete application implements all required interfaces.
 		try{
-			this.osFunction = (OSFunctionalityProvider)concreteApp;
+			this.osFunction = (AndroidFunctionalityWrapper)concreteApp;
 		}catch(ClassCastException cc){
 			Gdx.app.debug(TAG, CLASS_NAME + ".Main() :: concreteApp does not implement the Toaster interface. Toasting disabled.");
 			this.osFunction = null;
 		}
 
 		try{
-			this.cvProc = (CVProcessor)concreteApp;
+			this.cvProc = (ImageProcessor)concreteApp;
 		}catch(ClassCastException cc){
 			Gdx.app.error(TAG, CLASS_NAME + ".Main() :: concreteApp does not implement the CVProcessor interface. Quitting.");
 			Gdx.app.exit();

src/ve/ucv/ciens/ccg/nxtar/components/GeometryComponent.java

@@ -16,35 +16,23 @@
 package ve.ucv.ciens.ccg.nxtar.components;
 
 import com.artemis.Component;
-import com.badlogic.gdx.math.Quaternion;
+import com.badlogic.gdx.math.Matrix3;
 import com.badlogic.gdx.math.Vector3;
 
 public class GeometryComponent extends Component {
 	public Vector3 position;
-	public Quaternion rotation;
+	public Matrix3 rotation;
 	public Vector3 scaling;
 
 	public GeometryComponent(){
 		this.position = new Vector3();
-		this.rotation = new Quaternion(new Vector3(1.0f, 0.0f, 0.0f), 0.0f);
+		this.rotation = new Matrix3();
 		this.scaling = new Vector3(1.0f, 1.0f, 1.0f);
 	}
 
-	public GeometryComponent(Vector3 position){
+	public GeometryComponent(Vector3 position, Matrix3 rotation, Vector3 scaling){
 		this.position = new Vector3(position);
-		this.rotation = new Quaternion(new Vector3(1.0f, 0.0f, 0.0f), 0.0f);
+		this.rotation = new Matrix3(rotation);
-		this.scaling = new Vector3(1.0f, 1.0f, 1.0f);
-	}
-
-	public GeometryComponent(Quaternion rotation){
-		this.position = new Vector3();
-		this.rotation = new Quaternion(rotation);
-		this.scaling = new Vector3(1.0f, 1.0f, 1.0f);
-	}
-
-	public GeometryComponent(Vector3 position, Quaternion rotation, Vector3 scaling){
-		this.position = new Vector3(position);
-		this.rotation = new Quaternion(rotation);
 		this.scaling = new Vector3(scaling);
 	}
 }

src/ve/ucv/ciens/ccg/nxtar/components/MarkerCodeComponent.java

@@ -0,0 +1,28 @@
+/*
+ * Copyright (C) 2014 Miguel Angel Astor Romero
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package ve.ucv.ciens.ccg.nxtar.components;
+
+import com.artemis.Component;
+
+public class MarkerCodeComponent extends Component {
+	public int code;
+
+	public MarkerCodeComponent(int code) throws IllegalArgumentException{
+		if(code < 0 || code > 1024)
+			throw new IllegalArgumentException("Marker code must be between [0, 1024].");
+		this.code = code;
+	}
+}

src/ve/ucv/ciens/ccg/nxtar/components/MeshComponent.java

@@ -18,10 +18,10 @@ package ve.ucv.ciens.ccg.nxtar.components;
 import com.artemis.Component;
 import com.badlogic.gdx.graphics.Mesh;
 
-public class ModelComponent extends Component {
+public class MeshComponent extends Component {
 	public Mesh model;
 	
-	public ModelComponent(Mesh model){
+	public MeshComponent(Mesh model){
 		this.model = model;
 	}
 }

src/ve/ucv/ciens/ccg/nxtar/entities/BombGameEntityCreator.java

@@ -0,0 +1,32 @@
+/*
+ * Copyright (C) 2014 Miguel Angel Astor Romero
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package ve.ucv.ciens.ccg.nxtar.entities;
+
+public class BombGameEntityCreator extends EntityCreatorBase {
+	public BombGameEntityCreator(){
+		// TODO: Empty constructor.
+	}
+
+	@Override
+	public void createAllEntities() {
+		// TODO Auto-generated method stub
+	}
+
+	@Override
+	public void dispose() {
+		// TODO Auto-generated method stub
+	}
+}

src/ve/ucv/ciens/ccg/nxtar/entities/TestGameEntityCreator.java

@@ -15,8 +15,8 @@
  */
 package ve.ucv.ciens.ccg.nxtar.entities;
 
-import ve.ucv.ciens.ccg.nxtar.components.ModelComponent;
 import ve.ucv.ciens.ccg.nxtar.components.GeometryComponent;
+import ve.ucv.ciens.ccg.nxtar.components.MeshComponent;
 import ve.ucv.ciens.ccg.nxtar.components.ShaderComponent;
 import ve.ucv.ciens.ccg.nxtar.exceptions.ShaderFailedToLoadException;
 import ve.ucv.ciens.ccg.nxtar.graphics.shaders.CustomShaderBase;
@@ -30,7 +30,7 @@ import com.badlogic.gdx.graphics.VertexAttribute;
 import com.badlogic.gdx.graphics.VertexAttributes;
 import com.badlogic.gdx.graphics.VertexAttributes.Usage;
 import com.badlogic.gdx.graphics.g3d.utils.MeshBuilder;
-import com.badlogic.gdx.math.Quaternion;
+import com.badlogic.gdx.math.Matrix3;
 import com.badlogic.gdx.math.Vector3;
 
 public class TestGameEntityCreator extends EntityCreatorBase {
@@ -45,6 +45,7 @@ public class TestGameEntityCreator extends EntityCreatorBase {
 
 	@Override
 	public void createAllEntities() {
+		Matrix3 identity = new Matrix3();
 		Entity sphere;
 		Entity cube;
 		Entity capsule1;
@@ -52,6 +53,8 @@ public class TestGameEntityCreator extends EntityCreatorBase {
 
 		Gdx.app.log(TAG, CLASS_NAME + ".createAllEntities(): Started.");
 
+		identity.idt();
+
 		// Create the sphere.
 		Gdx.app.log(TAG, CLASS_NAME + ".createAllEntities(): Creating the meshes.");
 		builder = new MeshBuilder();
@@ -84,23 +87,23 @@ public class TestGameEntityCreator extends EntityCreatorBase {
 		// Create the entities.
 		Gdx.app.log(TAG, CLASS_NAME + ".createAllEntities(): Creating the enitites.");
 		sphere = world.createEntity();
-		sphere.addComponent(new GeometryComponent(new Vector3(0.5f, 0.5f, 0.0f)));
+		sphere.addComponent(new GeometryComponent(new Vector3(0.5f, 0.5f, 0.0f), identity, new Vector3(1.0f, 1.0f, 1.0f)));
-		sphere.addComponent(new ModelComponent(sphereMesh));
+		sphere.addComponent(new MeshComponent(sphereMesh));
 		sphere.addComponent(new ShaderComponent(singleLightPhongShader));
 
 		cube = world.createEntity();
-		cube.addComponent(new GeometryComponent(new Vector3(-0.5f, -0.5f, 0.0f), new Quaternion(new Vector3(1.0f, 1.0f, 0.0f), 0.0f), new Vector3(1.0f, 1.0f, 1.0f)));
+		cube.addComponent(new GeometryComponent(new Vector3(-0.5f, -0.5f, 0.0f), identity, new Vector3(1.0f, 1.0f, 1.0f)));
-		cube.addComponent(new ModelComponent(cubeMesh));
+		cube.addComponent(new MeshComponent(cubeMesh));
 		cube.addComponent(new ShaderComponent(singleLightPhongShader));
 
 		capsule1 = world.createEntity();
-		capsule1.addComponent(new GeometryComponent(new Vector3(-0.5f, 0.5f, 0.0f), new Quaternion(new Vector3(1.0f, 0.0f, 0.0f), 0.0f), new Vector3(1.5f, 1.0f, 1.0f)));
+		capsule1.addComponent(new GeometryComponent(new Vector3(-0.5f, 0.5f, 0.0f), identity, new Vector3(1.5f, 1.0f, 1.0f)));
-		capsule1.addComponent(new ModelComponent(capsuleMesh));
+		capsule1.addComponent(new MeshComponent(capsuleMesh));
 		capsule1.addComponent(new ShaderComponent(singleLightPhongShader));
 
 		capsule2 = world.createEntity();
-		capsule2.addComponent(new GeometryComponent(new Vector3(0.5f, -0.5f, 0.0f), new Quaternion(new Vector3(0.0f, 1.0f, 0.0f), 0.0f), new Vector3(1.0f, 1.5f, 1.0f)));
+		capsule2.addComponent(new GeometryComponent(new Vector3(0.5f, -0.5f, 0.0f), identity, new Vector3(1.0f, 1.5f, 1.0f)));
-		capsule2.addComponent(new ModelComponent(capsuleMesh));
+		capsule2.addComponent(new MeshComponent(capsuleMesh));
 		capsule2.addComponent(new ShaderComponent(singleLightPhongShader));
 
 		// Add the entities to the world.

src/ve/ucv/ciens/ccg/nxtar/interfaces/AndroidFunctionalityWrapper.java

@@ -15,7 +15,7 @@
  */
 package ve.ucv.ciens.ccg.nxtar.interfaces;
 
-public interface OSFunctionalityProvider{
+public interface AndroidFunctionalityWrapper{
 	public void showShortToast(String msg);
 	public void showLongToast(String msg);
 	public void enableMulticast();

src/ve/ucv/ciens/ccg/nxtar/interfaces/ImageProcessor.java

@@ -15,21 +15,25 @@
  */
 package ve.ucv.ciens.ccg.nxtar.interfaces;
 
-public interface CVProcessor{
+import com.badlogic.gdx.math.Matrix3;
-	public class CVMarkerData{
+import com.badlogic.gdx.math.Vector3;
+
+public interface ImageProcessor{
+	public class MarkerData{
 		public byte[] outFrame;
 		public int[] markerCodes;
-		// TODO: Add marker location data.
+		public Vector3[] translationVectors;
+		public Matrix3[] rotationMatrices;
 	}
 
-	public class CVCalibrationData{
+	public class CalibrationData{
 		public byte[] outFrame;
 		public float[] calibrationPoints;
 	}
 
-	public CVMarkerData findMarkersInFrame(byte[] frame);
+	public MarkerData findMarkersInFrame(byte[] frame);
-	public CVCalibrationData findCalibrationPattern(byte[] frame);
+	public CalibrationData findCalibrationPattern(byte[] frame);
 	public void calibrateCamera(float[][] calibrationSamples, byte[] frame);
 	public byte[] undistortFrame(byte[] frame);
-	public boolean cameraIsCalibrated();
+	public boolean isCameraCalibrated();
 }

src/ve/ucv/ciens/ccg/nxtar/states/CameraCalibrationState.java

@@ -19,7 +19,7 @@ import java.util.Arrays;
 
 import ve.ucv.ciens.ccg.nxtar.NxtARCore;
 import ve.ucv.ciens.ccg.nxtar.NxtARCore.game_states_t;
-import ve.ucv.ciens.ccg.nxtar.interfaces.CVProcessor.CVCalibrationData;
+import ve.ucv.ciens.ccg.nxtar.interfaces.ImageProcessor.CalibrationData;
 import ve.ucv.ciens.ccg.nxtar.network.monitors.VideoFrameMonitor;
 import ve.ucv.ciens.ccg.nxtar.utils.ProjectConstants;
 import ve.ucv.ciens.ccg.nxtar.utils.Size;
@@ -210,22 +210,22 @@ public class CameraCalibrationState extends BaseState{
 		frame = frameMonitor.getCurrentFrame();
 
 		// Apply the undistortion method if the camera has been calibrated already.
-		if(core.cvProc.cameraIsCalibrated()){
+		if(core.cvProc.isCameraCalibrated()){
 			frame = core.cvProc.undistortFrame(frame);
 		}
 
 		// Find the calibration points in the video frame.
-		CVCalibrationData data = core.cvProc.findCalibrationPattern(frame);
+		CalibrationData data = core.cvProc.findCalibrationPattern(frame);
 
 		// Disable the sampling button if the calibration pattern was not found.
-		if(data.calibrationPoints != null && !core.cvProc.cameraIsCalibrated()){
+		if(data.calibrationPoints != null && !core.cvProc.isCameraCalibrated()){
 			takeSampleButton.setDisabled(false);
 		}else{
 			takeSampleButton.setDisabled(true);
 		}
 
 		// If the user requested a sample be taken.
-		if(takeSample && !core.cvProc.cameraIsCalibrated() && data.calibrationPoints != null){
+		if(takeSample && !core.cvProc.isCameraCalibrated() && data.calibrationPoints != null){
 			// Disable sample taking.
 			takeSample = false;
 			Gdx.app.log(TAG, CLASS_NAME + ".render(): Sample taken.");

src/ve/ucv/ciens/ccg/nxtar/states/InGameState.java

@@ -22,10 +22,12 @@ import ve.ucv.ciens.ccg.nxtar.NxtARCore.game_states_t;
 import ve.ucv.ciens.ccg.nxtar.entities.EntityCreatorBase;
 import ve.ucv.ciens.ccg.nxtar.entities.TestGameEntityCreator;
 import ve.ucv.ciens.ccg.nxtar.graphics.RenderParameters;
-import ve.ucv.ciens.ccg.nxtar.interfaces.CVProcessor.CVMarkerData;
+import ve.ucv.ciens.ccg.nxtar.interfaces.ImageProcessor.MarkerData;
 import ve.ucv.ciens.ccg.nxtar.network.monitors.MotorEventQueue;
 import ve.ucv.ciens.ccg.nxtar.network.monitors.VideoFrameMonitor;
-import ve.ucv.ciens.ccg.nxtar.systems.RenderingSystem;
+import ve.ucv.ciens.ccg.nxtar.systems.MarkerPositioningSystem;
+import ve.ucv.ciens.ccg.nxtar.systems.MarkerRenderingSystem;
+import ve.ucv.ciens.ccg.nxtar.systems.ObjectRenderingSystem;
 import ve.ucv.ciens.ccg.nxtar.utils.ProjectConstants;
 
 import com.artemis.World;
@@ -173,7 +175,9 @@ public class InGameState extends BaseState{
 		entityCreator.setWorld(gameWorld);
 
 		entityCreator.createAllEntities();
-		gameWorld.setSystem(new RenderingSystem(), true);
+		gameWorld.setSystem(new MarkerPositioningSystem());
+		gameWorld.setSystem(new MarkerRenderingSystem(), true);
+		gameWorld.setSystem(new ObjectRenderingSystem(), true);
 
 		gameWorld.initialize();
 	}
@@ -186,13 +190,9 @@ public class InGameState extends BaseState{
 	public void render(float delta){
 		int w, h;
 		byte[] frame;
-		CVMarkerData data;
+		MarkerData data;
 		TextureRegion region;
 
-		// Update the game state.
-		gameWorld.setDelta(Gdx.graphics.getDeltaTime() * 1000);
-		gameWorld.process();
-
 		// Clear the screen.
 		Gdx.gl.glClearColor(1, 1, 1, 1);
 		Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
@@ -227,7 +227,7 @@ public class InGameState extends BaseState{
 		}
 
 		// Apply the undistortion method if the camera has been calibrated already.
-		if(core.cvProc.cameraIsCalibrated()){
+		if(core.cvProc.isCameraCalibrated()){
 			frame = core.cvProc.undistortFrame(frame);
 		}
 
@@ -236,6 +236,11 @@ public class InGameState extends BaseState{
 
 		// If a valid frame was fetched.
 		if(data != null && data.outFrame != null){
+			// Update the game state.
+			gameWorld.setDelta(Gdx.graphics.getDeltaTime() * 1000);
+			gameWorld.getSystem(MarkerPositioningSystem.class).setMarkerData(data);
+			gameWorld.process();
+
 			// Decode the video frame.
 			videoFrame = new Pixmap(data.outFrame, 0, w * h);
 			videoFrameTexture = new Texture(videoFrame);
@@ -260,7 +265,9 @@ public class InGameState extends BaseState{
 				// Render the current state of the game.
 				RenderParameters.setModelViewProjectionMatrix(camera3D.combined);
 				RenderParameters.setEyePosition(camera3D.position);
-				gameWorld.getSystem(RenderingSystem.class).process();
+				gameWorld.getSystem(MarkerRenderingSystem.class).setMarkerData(data);
+				gameWorld.getSystem(MarkerRenderingSystem.class).process();
+				gameWorld.getSystem(ObjectRenderingSystem.class).process();
 
 				Gdx.gl.glDisable(GL20.GL_DEPTH_TEST);
 			}frameBuffer.end();
@@ -325,6 +332,8 @@ public class InGameState extends BaseState{
 				headC.draw(core.batch);
 			}core.batch.end();
 		}
+
+		data = null;
 	}
 
 	@Override

src/ve/ucv/ciens/ccg/nxtar/systems/MarkerPositioningSystem.java

@@ -0,0 +1,77 @@
+/*
+ * Copyright (C) 2014 Miguel Angel Astor Romero
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package ve.ucv.ciens.ccg.nxtar.systems;
+
+import ve.ucv.ciens.ccg.nxtar.components.GeometryComponent;
+import ve.ucv.ciens.ccg.nxtar.components.MarkerCodeComponent;
+import ve.ucv.ciens.ccg.nxtar.interfaces.ImageProcessor.MarkerData;
+import ve.ucv.ciens.ccg.nxtar.utils.ProjectConstants;
+
+import com.artemis.Aspect;
+import com.artemis.ComponentMapper;
+import com.artemis.Entity;
+import com.artemis.annotations.Mapper;
+import com.artemis.systems.EntityProcessingSystem;
+import com.badlogic.gdx.Gdx;
+
+public class MarkerPositioningSystem extends EntityProcessingSystem {
+	@Mapper ComponentMapper<MarkerCodeComponent> markerMapper;
+	@Mapper ComponentMapper<GeometryComponent> geometryMapper;
+
+	private static final String TAG = "MARKER_POSITIONING_SYSTEM";
+	private static final String CLASS_NAME = MarkerPositioningSystem.class.getSimpleName();
+
+	private MarkerData markers;
+
+	@SuppressWarnings("unchecked")
+	public MarkerPositioningSystem(){
+		super(Aspect.getAspectForAll(MarkerCodeComponent.class, GeometryComponent.class));
+
+		markers = null;
+	}
+
+	public void setMarkerData(MarkerData markers){
+		this.markers = markers;
+	}
+
+	@Override
+	protected void process(Entity e) {
+		MarkerCodeComponent marker;
+		GeometryComponent   geometry;
+
+		if(markers == null)
+			return;
+
+		Gdx.app.log(TAG, CLASS_NAME + ".process(): Getting components.");
+		marker   = markerMapper.get(e);
+		geometry = geometryMapper.get(e);
+
+		Gdx.app.log(TAG, CLASS_NAME + ".process(): Processing markers.");
+		for(int i = 0; i < ProjectConstants.MAXIMUM_NUMBER_OF_MARKERS; i++){
+			if(markers.markerCodes[i] != 1){
+				if(markers.markerCodes[i] == marker.code){
+					Gdx.app.log(TAG, CLASS_NAME + ".process(): Processing marker code " + Integer.toString(markers.markerCodes[i]) + ".");
+					geometry.position.set(markers.translationVectors[i]);
+					geometry.rotation.set(markers.rotationMatrices[i]);
+				}
+			}else{
+				Gdx.app.log(TAG, CLASS_NAME + ".process(): Skipping marker number " + Integer.toString(i) + ".");
+			}
+		}
+
+		markers = null;
+	}
+}

src/ve/ucv/ciens/ccg/nxtar/systems/MarkerRenderingSystem.java

@@ -0,0 +1,108 @@
+package ve.ucv.ciens.ccg.nxtar.systems;
+
+import ve.ucv.ciens.ccg.nxtar.components.GeometryComponent;
+import ve.ucv.ciens.ccg.nxtar.components.MarkerCodeComponent;
+import ve.ucv.ciens.ccg.nxtar.components.MeshComponent;
+import ve.ucv.ciens.ccg.nxtar.components.ShaderComponent;
+import ve.ucv.ciens.ccg.nxtar.graphics.RenderParameters;
+import ve.ucv.ciens.ccg.nxtar.interfaces.ImageProcessor.MarkerData;
+import ve.ucv.ciens.ccg.nxtar.utils.ProjectConstants;
+
+import com.artemis.Aspect;
+import com.artemis.ComponentMapper;
+import com.artemis.Entity;
+import com.artemis.annotations.Mapper;
+import com.artemis.systems.EntityProcessingSystem;
+import com.badlogic.gdx.Gdx;
+import com.badlogic.gdx.graphics.GL20;
+import com.badlogic.gdx.math.Matrix4;
+
+public class MarkerRenderingSystem extends EntityProcessingSystem {
+	@Mapper ComponentMapper<MarkerCodeComponent> markerMapper;
+	@Mapper ComponentMapper<GeometryComponent> geometryMapper;
+	@Mapper ComponentMapper<ShaderComponent> shaderMapper;
+	@Mapper ComponentMapper<MeshComponent> meshMapper;
+
+	private static final String TAG = "MARKER_RENDERING_SYSTEM";
+	private static final String CLASS_NAME = MarkerRenderingSystem.class.getSimpleName();
+
+	/**
+	 * <p>A matrix representing 3D translations.</p>
+	 */
+	private Matrix4 translationMatrix;
+
+	/**
+	 * <p>A matrix representing 3D rotations.</p>
+	 */
+	private Matrix4 rotationMatrix;
+
+	/**
+	 * <p>A matrix representing 3D scalings.</p>
+	 */
+	private Matrix4 scalingMatrix;
+
+	/**
+	 * <p>The total transformation to be applied to an entity.</p>
+	 */
+	private Matrix4 combinedTransformationMatrix;
+
+	MarkerData markers;
+
+	@SuppressWarnings("unchecked")
+	public MarkerRenderingSystem(){
+		super(Aspect.getAspectForAll(MarkerCodeComponent.class, GeometryComponent.class, ShaderComponent.class, MeshComponent.class));
+
+		markers = null;
+		translationMatrix = new Matrix4().setToTranslation(0.0f, 0.0f, 0.0f);
+		rotationMatrix = new Matrix4().idt();
+		scalingMatrix = new Matrix4().setToScaling(0.0f, 0.0f, 0.0f);
+		combinedTransformationMatrix = new Matrix4();
+	}
+
+	public void setMarkerData(MarkerData markers){
+		this.markers = markers;
+	}
+
+	@Override
+	protected void process(Entity e) {
+		MarkerCodeComponent marker;
+		GeometryComponent geometry;
+		ShaderComponent shaderComp;
+		MeshComponent meshComp;
+
+		if(markers == null)
+			return;
+
+		Gdx.app.log(TAG, CLASS_NAME + ".process(): Getting components.");
+		marker = markerMapper.get(e);
+		geometry = geometryMapper.get(e);
+		shaderComp = shaderMapper.get(e);
+		meshComp = meshMapper.get(e);
+
+		Gdx.app.log(TAG, CLASS_NAME + ".process(): Processing markers.");
+		for(int i = 0; i < ProjectConstants.MAXIMUM_NUMBER_OF_MARKERS; i++){
+			if(markers.markerCodes[i] != 1){
+				if(markers.markerCodes[i] == marker.code){
+					Gdx.app.log(TAG, CLASS_NAME + ".process(): Rendering marker code " + Integer.toString(markers.markerCodes[i]) + ".");
+					// Set the geometric transformations.
+					translationMatrix.setToTranslation(geometry.position);
+					rotationMatrix.set(geometry.rotation);
+					scalingMatrix.setToScaling(geometry.scaling);
+					combinedTransformationMatrix.idt().mul(scalingMatrix).mul(rotationMatrix).mul(translationMatrix);
+					RenderParameters.setTransformationMatrix(combinedTransformationMatrix);
+
+					// Render the marker;
+					shaderComp.shader.getShaderProgram().begin();{
+						shaderComp.shader.setUniforms();
+						meshComp.model.render(shaderComp.shader.getShaderProgram(), GL20.GL_TRIANGLES);
+					}shaderComp.shader.getShaderProgram().end();
+				}
+			}else{
+				Gdx.app.log(TAG, CLASS_NAME + ".process(): Skipping marker number " + Integer.toString(i) + ".");
+			}
+		}
+		
+		markers = null;
+	}
+
+}

src/ve/ucv/ciens/ccg/nxtar/systems/ObjectRenderingSystem.java

@@ -16,7 +16,8 @@
 package ve.ucv.ciens.ccg.nxtar.systems;
 
 import ve.ucv.ciens.ccg.nxtar.components.GeometryComponent;
-import ve.ucv.ciens.ccg.nxtar.components.ModelComponent;
+import ve.ucv.ciens.ccg.nxtar.components.MarkerCodeComponent;
+import ve.ucv.ciens.ccg.nxtar.components.MeshComponent;
 import ve.ucv.ciens.ccg.nxtar.components.ShaderComponent;
 import ve.ucv.ciens.ccg.nxtar.graphics.LightSource;
 import ve.ucv.ciens.ccg.nxtar.graphics.RenderParameters;
@@ -31,42 +32,73 @@ import com.badlogic.gdx.graphics.GL20;
 import com.badlogic.gdx.math.Matrix4;
 import com.badlogic.gdx.math.Vector3;
 
-public class RenderingSystem extends EntityProcessingSystem {
+/**
+ * <p>Entity processing system in charge of rendering 3D objects using OpenGL. The
+ * entities to be rendered must have a geometry, shader and mesh component associated.</p>
+ */
+public class ObjectRenderingSystem extends EntityProcessingSystem {
 	@Mapper ComponentMapper<GeometryComponent> geometryMapper;
 	@Mapper ComponentMapper<ShaderComponent> shaderMapper;
-	@Mapper ComponentMapper<ModelComponent> modelMapper;
+	@Mapper ComponentMapper<MeshComponent> modelMapper;
 
+	private static final Vector3 LIGHT_POSITION = new Vector3(2.0f, 2.0f, 4.0f);
+	private static final Color AMBIENT_COLOR = new Color(0.0f, 0.1f, 0.2f, 1.0f);
+	private static final Color DIFFUSE_COLOR = new Color(1.0f, 1.0f, 1.0f, 1.0f);
+	private static final Color SPECULAR_COLOR = new Color(1.0f, 0.8f, 0.0f, 1.0f);
+	private static final float SHINYNESS = 50.0f;
+
+	/**
+	 * <p>A matrix representing 3D translations.</p>
+	 */
 	private Matrix4 translationMatrix;
+
+	/**
+	 * <p>A matrix representing 3D rotations.</p>
+	 */
 	private Matrix4 rotationMatrix;
+
+	/**
+	 * <p>A matrix representing 3D scalings.</p>
+	 */
 	private Matrix4 scalingMatrix;
+
+	/**
+	 * <p>The total transformation to be applied to an entity.</p>
+	 */
 	private Matrix4 combinedTransformationMatrix;
 
 	@SuppressWarnings("unchecked")
-	public RenderingSystem() {
+	public ObjectRenderingSystem() {
-		super(Aspect.getAspectForAll(GeometryComponent.class, ShaderComponent.class, ModelComponent.class));
+		super(Aspect.getAspectForAll(GeometryComponent.class, ShaderComponent.class, MeshComponent.class).exclude(MarkerCodeComponent.class));
 
-		RenderParameters.setLightSource1(new LightSource(new Vector3(2.0f, 2.0f, 4.0f), new Color(0.0f, 0.1f, 0.2f, 1.0f), new Color(1.0f, 1.0f, 1.0f, 1.0f), new Color(1.0f, 0.8f, 0.0f, 1.0f), 50.0f));
+		RenderParameters.setLightSource1(new LightSource(LIGHT_POSITION, AMBIENT_COLOR, DIFFUSE_COLOR, SPECULAR_COLOR, SHINYNESS));
 
 		translationMatrix = new Matrix4().setToTranslation(0.0f, 0.0f, 0.0f);
-		rotationMatrix = new Matrix4().setToRotation(1.0f, 0.0f, 0.0f, 0.0f);
+		rotationMatrix = new Matrix4().idt();
 		scalingMatrix = new Matrix4().setToScaling(0.0f, 0.0f, 0.0f);
 		combinedTransformationMatrix = new Matrix4();
 	}
 
+	/**
+	 * <p>Renders the entity passed by parameter, calculating it's corresponding geometric
+	 * transformation and setting and calling it's associated shader program.</p>
+	 * 
+	 * @param e The entity to be processed.
+	 */
 	@Override
 	protected void process(Entity e) {
 		GeometryComponent geometryComponent;
 		ShaderComponent shaderComponent;
-		ModelComponent modelComponent;
+		MeshComponent meshComponent;
 
 		// Get the necessary components.
 		geometryComponent = geometryMapper.get(e);
-		modelComponent = modelMapper.get(e);
+		meshComponent = modelMapper.get(e);
 		shaderComponent = shaderMapper.get(e);
 
 		// Calculate the geometric transformation for this entity.
 		translationMatrix.setToTranslation(geometryComponent.position);
-		rotationMatrix.rotate(geometryComponent.rotation);
+		rotationMatrix.set(geometryComponent.rotation);
 		scalingMatrix.setToScaling(geometryComponent.scaling);
 		combinedTransformationMatrix.idt().mul(scalingMatrix).mul(rotationMatrix).mul(translationMatrix);
 
@@ -76,7 +108,7 @@ public class RenderingSystem extends EntityProcessingSystem {
 		// Render this entity.
 		shaderComponent.shader.getShaderProgram().begin();{
 			shaderComponent.shader.setUniforms();
-			modelComponent.model.render(shaderComponent.shader.getShaderProgram(), GL20.GL_TRIANGLES);
+			meshComponent.model.render(shaderComponent.shader.getShaderProgram(), GL20.GL_TRIANGLES);
 		}shaderComponent.shader.getShaderProgram().end();
 	}
 }

src/ve/ucv/ciens/ccg/nxtar/utils/ProjectConstants.java

@@ -36,6 +36,7 @@ public abstract class ProjectConstants{
 	public static final int     MENU_BUTTON_FONT_SIZE;
 	public static final String  FONT_CHARS                 = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890";
 
+	public static final int     MAXIMUM_NUMBER_OF_MARKERS  = 5;
 	public static final int     CALIBRATION_PATTERN_POINTS = 54;
 	public static final int     CALIBRATION_SAMPLES        = 10;